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G. H. DIMOND & W. F. DIAL.

AUTOMATIC TENSION FOR SEWING MACHINES.

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G. H. DIMOND 8: W. F. DIAL.

AUTOMATIO TENSION FOR SEWING MACHINES. ,No. 305,438.

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GEORGE H. DIMOND AND WVILBUR F. DIAL, OF BRIDGEPORT, CONNECTICUT,

ASSIGNORS TOWVHEELER 8t WILSON MANUFACTURING COMPANY, OF'

SAME PLACE.

AUTOMATIC TENSION FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 305,438, datedSeptember 23, 1884.

Application filed December 14, 1883. (ModeL) C To aZZ whom it mayconcern:

Be it known that we, GEORGE H. DIMoND and WILBUR F. DIAL, of Bridgeport,county of Fairlield, State of Connecticut, have invented an Improvementin Automatic Tensions for SewingMachines, of which the followingdescription, in connection with the accompanying drawings, is aspecification, like letters on the drawings representing like 10 parts.

This invention relates to that class of tension mechanism which isadapted to automatieally hold and release the needle-thread, a lowingonly a quantity thereof snfficient to form a stitch to be drawn from thetension device and spool by the take-up at each revolution of the mainshaft of the machine. Means are herein provided to release theneedlethread from the tension device at the will of the operator, suchmeans cooperating with the lever used to lift the presser-bar and foot,so that while the presscr-foot is raised to remove from or place underit the work, the needle-thread may be freely drawn through 2 5 thetension device and eye of the needle.

Figure 1, in side elevation,represents asewing-machine, to which theinvention to be herein described is applied; Fig. 2, an opposite sideview of Fig. 1; Figs. 3, 4, and 5 are enlarged sectional details of thedevices in the line a: m, Fig. 2, the said figures showing the parts indifferent positions during the oscillation of the needle-baractuatingrockshaft. Fig. 6 is an enlarged sectional detail on the line 00 m, Fig.2; and Fig. 7 is a partial sectionand plan view of parts shown in Fig.5. e

In this our invention we employ a tension device composed, essentially,of one or more disks or plates, a spindle provided bet-ween its endswith a fixed collar, a shoe or block at the inner end of the spindle,two springs, and a chambered washer, one of the said springs beingplacedat one and the other at the opposite side of the saidcollar, one springacting to draw the inner side of the said collar against the said disksor plates,- while the other spring acts to force the said chamberedwasher against the said disks whenever the said washer is not pushed bythe said collar and spindle back away from the said disks or d,slack-controller (1, eye (1, and stud f are plates. The shoe or blockattached to the spindle is adapted to be struck by a cam on theneedle-bar-operating shaft, it moving the said spindle in opposition tothat one of its springs which is effective to grasp the needlethreadpositively, as will be described. The lifting of the resser-foot througha system of levers, one of which is made as a partial sleeve, moves thespindle and relieves the disks or plates from the pressure of both ofthe said springs, at which time the needle-thread is free to be drawnfrom or past the disks and from the spool without tension. The arm A,bed B, rotating shaft B, eccentric a, eccentricstrap a, arm aneedle-bar,-actuating rockshai't C, arm af, link a needle-bar b,bearings I) 5 for the shaft C, the cam-hub D, take-up lever D, pivotedat (l, and the rotating hook 0 common to theNVhecler Wilson machine, 7so need not be herein further described. The needle-thread shown indotted lines, Fig. 1, is taken from spool E across between the disks orplatesf f of the tension device; then partially aboutthc stud f", backbetween the said disks f f, over the thread-controller d, and wire-eyed", and through an eye in the take-up lever D, and thence through usualguide eyes or devices to and through the eye of the needle. The disk fis shown as placed upon the hub of the disk f, and the latter is placedupon a spindle, 0, provided with a fixed collar, 6, and an oil stop orcheck, a the said spindle having attached to it, by screw 6", so as toform part of it, a shoe or block, 9. The spindle c is provided with ascrew-thread, c, which receives a nut, e, and between the said nut andthe outer side of the collar 6 is placed a spring, c, and a chamberedwasher, 0 e011- caved at its side next the collar 0 for a depth inexcess of the thickness of the said collar. The face of the washer 0where extended beyond the collar 0, receives against one side of it thespring (1, so that when the collar and 5 washer are not in directcontact, the rear side or face of the said washer will rest against thedisk f and act to force it against the disk f, it in turn restingagainst the arm A, and the needle-thread will be held under a constant,but greater or less degree of tension, the force of which will bemeasured by the adjustment of the spring 6. or projection, g, whichenters a recess or chamber, in the frame part A, where it is surroundedby a suitable spring, 9 (preferably a rather stiff spiral spring,) thesole purpose and normal tendency of which is to force the said shoe orblock toward the cam F, fast on the shaft 0, and draw the spindle e inthe same direction, so that the rear side of the collar e, fixedthereto, will act against the disk f, to cause the thread between it andthe disk f to be held by a tension augmented by the strength of thespring so long as the cam F does not touch the shoe or block 9, or, thelatter is not held back away from the said cam by the catch-lever g,pivoted at g on the sleeve H, to be described, which, with its attachedlugs, constitute a lever. Then the force of the spring is effectual onthe disks or plates ff, the needle-thread between them will bepositively clamped, so that it cannot be drawn from the spool by thetake-up lever D or by-other means. The oscillating shaft 0 is hereinmade the fulcrum for the sleeve H, provided at its front end, next theThe lug h" is acted upon by a suitable spring, h", so as to normallyhold the lug h against the short arm of the tension-releasing lever at,having its fulcrum at m on the frame part A,

so that when the said lever m is turned upon its fulcrum m, as will bedescribed, during the lifting of the presser-foot bar at and presserfootW, the sleeve H will be turned and the lug h will act against the shoeor block 9, as in Fig. 3, and cause it and the spindle e to be movedaway from the shaft Gfor a sufficient distance to completely remove thecollar 6 from the disk or plate f and force the said collar against thewasher 6 causing its removal from the disks or plates ff, thus leavingthe needle-thread between the said disks or plates f f free from alltension, in order that it may at such time be drawn freely from thetension device and spool through the eye of the needle, as is customarywhen the work is tobe removed from or work is to be supplied under thepresser-foot. The tensionreleasing lever m, having its fulcrum at m, isacted upon by a roll or stud, m, on the usual 'presser-bar lifting-leveron, having its fulcrum at in", so that when the said lever m is turned,as in Figs. 1 and 2, the roll or stud m will act on the lever m andcause it to turn the sleeve, as shown in Figs. 1 and 3. The catch-leverg, pivoted on the sleeve H at 9 and provided with a pin or projection,is acted upon by a spring, 9', (shown best in Fig. 3,) the normaltendency of which is to hold the lever g in the position with relationto the said sleeve as represented in Fig. 3, the said catch-lever flyingup at the rear of the block g whenever it is pressed fully back by thesleeve H, as in Fig. 3. The length of the lever and its pivotal pointare such with relation to the The shoe or block 9 has a pin block 9 andcam F that the spring 9 is permitted to fully operate the lever 9 onlywhen the block 9 is pushed fully back away from the shaft 0 by the lugh", such movement of the said block causing the spindle to be moved farenough to remove the collar 6 from the disks or plates, and cause thesaid collar, acting on the washer 6 to removeit from the said disks orplates f f, to thus release them from all pressure and leave theneedle-thread entirely free to be drawn from the tension device andspool, such being done only when the presser-foot is lifted for theremoval of the work from or its insertionunder the presserfoot. Shouldthe presser-bar be lowered and the lug h be turned away from the block7, the catch-lever g, occupying the position as shown in Fig.- 3, willretain the disks or plates f f from acting to hold or obstruct the freerendering of the'needle-thread between them; but as soon as the machineis started from its highest position downward into its lowest position,Fig. 4, will strike the pin or projection g of the catch-lever g andremove the end of the same from contact with the block 9, permitting thespring 9 to act and force the said block against the said camthen in itslowestposition, and the disks ff will be forced together bya pressuredue to the spring 6, the tension then produced by the said spring beingthat which is to be the minimum tension upon the needle-thread whensewing, such tension being effectual in keeping the needlethreadsufficiently taut to be carried properly about the usual disk-bobbin inthe-rotating hook. As the cam F thereafter ascends from its lowestposition, the catch-lever having been relieved from holding the blockthe catch-lever will strike against the lower end of the block, as inFig. 5, and will not again act to hold the block until the latter hasbeen fully moved backward by the lug h", when the presser-foot is againfully lifted, and,as the corner 2 at the lower end of the actingface ofthe cam F passes the high point 3 of the block 9, the full force of thespring will act to draw the collar 6 against the disks or plates f f andclamp or grip the needle-thread positively. Assuming the position of theparts to be as in Figs. 1 and 3, with the presser-foot lifted and theneedle-bar in its highest posilatter will be lowered thereon, and, as iscus- Y tomary, the end of the needle-thread beyond the eye of the needlewill be drawn backward away from the operator, and will be held be- 1tween the presser-foot and the said material. Lowering the presser-footwill relieve the block 9 from the pressure against it of the lug .h thespring k then being free to act to partly rotate the sleeve H; but thecatch-lever will, by its spring still be held up against and retain theblock an the cam F positively disengagesit. If the machine is now turnedin the proper direction,the cam F and the needle bar will begin todescend, and the upper end of the take-up lever D will begin to movebackward or away from the tension disks or plates f f, and as the threadat the sewingpoint is held under the presser-foot the said take-up leverwill draw the thread from the. direction of the least resistance, whichwill be from the spool, until the eye of the needle arrivessubstantially at the throat-plate, and the take-up lever arrives nearlyto the limit of the first part of its backward'stroke, such movementdrawing from the spool all the thread which is required for the nextstitch. Theneedle-bar and needle then further descend, while theloop ofneedle-thread is taken by the usual rotating hook, and when in its lowerposition the cam F in its descent strikes the projecting pin 9 on thecatch-lever and removes the end of said catch-lever from the block 9,which permits the same, under the action of the spring to move towardthe cam F, then in its lowest position, and consequcntly the block 9 canmove toward the shaft C only far enough to permit the collar 0 on thespindle to release the washer 0 the collar 0 at such time not actingupon the disk f, but occupying a position, as shown in Fig.

4, the pressure due to the spring e being then thrown upon the washer cand the disks or plates f f, and therefore the needle-thread will besubjected to but its minimum tension, or will only be checked, notgripped and held positively, while the take-up lever moves to give upslack thread to the hook,

it then acting to draw the loop of needle thread down and about theusual bobbin. The take-up lever having been thus moved to give upsufficient thread to form aloop, the cam F, on rising, retires from theblock 9, allowing the spring 9" to come into action to move the spindlee and collar 0 and effect the positive grip of the needle-thread, whilethe take-up lever D is again moved backward. Just before the take-uplever commences to be moved backward a second time to draw up the loopthe needle-bar has risen far enough and the cam I F'high enough torelease the block 9, thus permitting the spindle e to be moved to clampthe thread, and the thread is so held clamped until the take-up leverhas nearly completed its backward movement, at which time the descent ofthe needle-bar and cam F causes the latter to again strike the block 9,thus releasing the needle-thread just as the take-up lever is completingits movement, such release of the, needle-thread, while thetake-up levertravels over about three-sixteenths of an inch, permittin g theneedle-thread to render freely from the disks and spool. By the use ofthe catchlever the take-up lever is enabled, during the formation of thefirst stitch, to draw from the spool sufficient thread for such stitchbefore the thread is positively clamped.

It is obvious that the spring 9 might be placed directly upon thespindle e. Thedisks or plates f f do not necessarily rotate, but

merely act to produce friction on the needlethread between them, andwhile we prefer to use two disks or plates we desire it to be understoodthat the disk f might be omitted, the inner side of the disk f thenresting opposite or with its face upon the arm A.

We claim 1. In a sewing-machine, a tension disk or plate, a chamberedwasher, a spindle provided with a collar, a spring pressing the washeragainst the disk or plate when the latter is not held back by the saidcollar, and a second spring acting to force the spindle and collaragainst the disk or plate, and the latter against the needle-thread,combined with a cam and a shoe or block interposed between the cam andspindle and acted upon directly by the cam, substantially as described.

2. In a sewing-machine, a tension disk or plate, a chambered washer, aspindle provided with a collar, a spring pressing the said washeragainst the disk or plate when the latter is not held back by the saidcollar, and a second spring acting to force the spindle and collaragainst the disk or plate and the latter against the needle-thread,combined with a cam, a block interposed between the spindle and cam, anda sleeve co-operatin g with the block, and feeding and stitch-formingmechanisms, sub stantially as and for the purpose described.

In a tension mechanism, the disks or plates, the spindle e, and aspring, to move it to clamp the disks or plates together, and a catch tohold the spindle and relieve the disks or plates from the tension due tothe said spring, combined with means to release the said catch from thespindle as the needle-bar descends to draw thread for a first stitch,substantially as described.

4. The spindle, its collar, the chambered washer and spring 6, and thedisks or plates operated upon by the said washer, combined with aspring, 9 and with means to move the said spindle in a directionopposite its movement due to the pressure of the latter spring,substantially as described.

5. The lever m, adapted to be actuated by the usual presser-barlifti11glever, and the sleeve or lever H, provided with lugs, as described,combined with a tension mechanism, whereby the lifting of thepresser-bar acts to turn the said sleeve and causes the disk f of thetension mechanism to be relieved from its hold upon the needle-thread,substantially as described.

6. The sleeve or lever H and the catch-lever 9, pivoted upon it, andspring to move it, combined with the block and spindle and disks, thesaid catch-lever, by the movement of the said sleeve, being put inposition to act upon and hold the block and spindle, as described.

7. In a tension mechanism, a tension disk or plate, a chambered washer,and a spindle provided with a collar, combined with two Intestimonywhereof we have signed our springs, one of which is adapted. torpressthe names to this'spec'ificationin the presence of IO said washeragainst the disk or plate when the two subscribing witnesses.

latter is not held back by the said collar, the GEORGE H. DIMON-D. otherspring acting to force the spindle and WILBUR F. DIAL. collar againstthe disk or plate and the latter Witnesses:

against the needle-thread, substantially as de LOUIs H. BAKER,

scribed.

GEO. E. LINCOLN.

